Hydrotreating processes for removing solid as well as dissolved metallic contaminants are known in the art. For instance, in European Pat. No. 399,592 a hydrotreating process is disclosed for the removal of solid and dissolved contaminants using as the catalyst porous inorganic oxide particles having a surface area of at most 1 m.sup.2 /g and a pore volume of at least 0.1 ml/g in pores having a diameter of at least 10 microns. The inorganic oxide may additionally contain oxides or sulfides of metals of Group VA, VIA and/or VIII. From Japanese Pat. No. 05/184941 a hydrotreating process for removing solids and dissolved contaminants is known, wherein a catalyst is used having a surface area above 5 m.sup.2 /g, a pore volume of 0.1 ml/g in micropores having a diameter of at least 0.004 micron (40 .ANG.) and a void ratio of 30 to 70%. The catalyst may also additionally contain oxides or sulfides of metals of Group V, VI and/or VIII. In U.S. Pat. No. 3,947,347 a hydrotreating process for removing metallic contaminants from a hydrocarbon feedstock is disclosed, in which process a catalyst is used which is free of any hydrogenating component and which has a surface area of from 1 to 20 m.sup.2 /g and pores having an average diameter of from 0.1 to 1 micron (1,000 to 10,000 .ANG.).
The present invention aims to provide a hydrotreating process for the simultaneous removal of solid contaminants and dissolved metallic contaminants wherein this catalyst can suitably be used. In this hydrotreatment process solid, as well as, dissolved metallic contaminants should be adequately removed from any hydrocarbon oil fraction ranging from naphtha to residual oils, whereby long operation times with a minimized pressure drop across the catalyst bed are attained. The present invention, accordingly, aims to provide a catalyst having an increased uptake capacity for metallic contaminants, in particular an increased solids uptake capacity, thus allowing longer operation times and lower pressure drop when used in a process for hydrotreating hydrocarbon oils containing such contaminants.
It has been found that a catalyst comprising a porous inorganic refractory oxide and meeting specific requirements as regards its pore volume, microporosity, macroporosity and surface area can achieve these aims.